2g idle issues

[974g63t]

A few months ago my 2g GST slipped timing. I had the head rebuilt, replaced the water pump, and replaced the belt of course. After its all said and done, I have an idle issue. The car will idle around 750-800 and will lope. It never loped before I had the head rebuilt. My CEL is on too. The codes are: Fuel Pressure solenoid, Cat below efficiency, and random misfire in cyl. 1. (Sorry, I don't have the specific code #'s).
Can anyone tell me why I am loping?

Mods:
3" turbo back exhaust (no cat)
K&N filter and chrome intake pipe

 

[sprmotohooligan]

Are you still on the stock fuel pressure regulator or do you have an AFPR on the car?

 

[974g63t]

ya the FPR is stock

I might add, though, that I've checked the timing and when the crank is on 0 and cyl. 1 is at TDC the timing marks on the cams are touching but the marks are not flush with the head. Is the timing slightly off? I've been told the timing may be half a tooth off.





SOLVED: Timing was off a tooth.